Phoenix Tropicals Gardening

[phoenixtropicals]

Look Amadio. Here is your post.

http://phoenixtropicals.com/phpbb/viewtopic.php?t=461

Frost cloth, plus plastic (when it gets below 30°F) , and light bulbs imagine that! You were way ahead of me.

I have found that with my larger trees I don't need a support structure. If the branch tips get beaten up a bit its not that much of concern for me.

I get my frost cloth from these guys and take a 100 ft. by 20 ft. roll and cut it into 20x20's.

http://www.berryhilldrip.com/GG40-is-a-Medium-Weight-Cover.-Protects-down-to-22-degrees-F.-Transmits-60-Light.html

For the plastic overlay I bought 1 mill 10x20 ft. plastic painters drop cloth. To get a 20x20 sheet I connect two pieces together with duct tape.

With this size of cover I can cover up to a 10 ft. tree. I had to take about 3 ft. off my mangoes to cover them for this latest freeze. Once they get bigger I'll just have to save the bottom I guess.

I use a 75 watt incandescent bulb with a clamp light socket and thermostat to turn them on.

By the way. The cherry trees I got from you seem to think all this cold weather is great unlike my mangoes.

[ajbcirc]

It's going to be a rough next few nights. This cold snap isn't expected to clear until Tuesday morning.

Temps dropped to 25 degrees by 6am this morning here in Scottsdale near Shea and the 101. Weather Underground had us pegged for a low of 28. Tonight, we're scheduled for 25, so we may see 21-22. For the first time since the last big frost in December/January of 2010-11, I covered up some of my Australian desert plants like my Blue Emus. My Mexican Cream guavas. courtesy of Don from a few years back, are under thick painter tarps and covered in C7 Christmas lights and have survived round one unscathed -- we'll see how Round 2 goes tonight. I'm curious to see how my Guamúchil (Pithecellobium dulce) tree does, as it's gone dormant and I haven't protected it through this entire cold snap.

I used to think we would get these sort of extremes ever five years or so. The seem to be coming more frequently; almost every other year. I'm not a fan of the global warming theory, especially with this mega cold snap occuring, but there may be some truth to the notion that we're undergoing some degree of climate change.

[Amadioranch]

Ha! Yeah we have to be pretty serious about frost structures out here because it really does average 10 degrees colder than most everywhere else. Actually those structures are what I used last year and I am using a completely different system this year. And thankfully so, those were only good for maybe 5-8 degrees below freezing, if I was using those now id have alot of very dead mangoes. THey were also too much trouble getting the covers on and off. Tho they would work very well for most.

Im so happy that the cherries worked out so well for everyone. Mine did fantastic also, so much so that ive ordered in a higher chill Rainer to try. Should be coming bare root any day now.

[phoenixtropicals]

I haven't protected my guamuchile either, except for burying its base in mulch, and it looks good so far.

What is your new type structure Amadio? How is it different than incandescent bulb, plus frost cloth, plus plastic?

[phoenixtropicals]

27° F here and 30°F in Phoenix. Weather.com right again and AZ central and local news wrong. I put a recording thermometer in my frost tent for my mango last night. It will be interesting to see what that reports.

[ajbcirc]

24.5 here at Shea and the 101 overnight. Tonight (Monday->Tuesday) is scheduled to be the coldest of the four nights.

[phoenixtropicals]

Everywhere I look has Tuesday morning in the mid 30's. Significantly warmer than last night. Except for AZ central. What's with that?

[phoenixtropicals]

It appears my frost tent was not working all that well. My thermometer recorded 2 hours inside at 27°F last night, even with frost cloth, plus plastic, plus light. My mango leaves show it too. Seems like the wood is still in good shape though, but that just might take longer to show. Apparently I need more insulation. I don't have a curve for outside the tent so I don't now how the rate of cooling off was affected.

Maybe next time I'll forgo the electric power and go for some real insulation instead. Season greenhouse maybe? It sure is hard to keep things warm in these conditions.

[phoenixtropicals]

30°F this morning.

[Amadioranch]

Ugly

[phoenixtropicals]

Yikes. I hope that's outside your frost tent.

Has anyone tried using a space blanket? After seeing how horrible plain plastic worked it seems like the radiation part of the heat transfer is very very significant. I just bought some on line, they are relatively cheap, and I'm going to test them out with my recording thermometer. I think I will try them between frost cloth and plastic. The plastic on the outside would mostly just protect the space blanket from the wind, while the frost cloth on inside would still provide some conduction loss prevention plus serve as a good platform to clip on the other layers.

Of course its getting warmer out but I should still be able to see how it affects temperature loss. That would be really great if I could bypass using lights if it works that well.

Real space blankets are coated on both sides. The inside reflects heat back and the outside layer of aluminum minimizes the emmission of heat. I saw some that only had one side with the aluminum layer, but I'm going to try the real thing.

[myamberdog]

PT - a very smart experiment and one I'll want to hear
more about....

hmmmm....maybe I'll google 'spaceblankets" to see what comes up....


myamberdogg

[phoenixtropicals]

Frost Tent Performance: Tuesday night January 15-16

Below are pictures of my frost tent, the tall one, and a graph of my temperature readings. The tent included the following. A 75 watt light bulb, a heavy frost cloth, with a plastic painters drop cloth on the outside of it, topped off with a bed sheet.

I have two USB recording thermometers and fairly good quality ones at that. Below are my numbers for last Monday night. The blue is inside my frost tent. The purple is outside in the open yard under the sky.

I checked the low on a separate thermometer under the eave of my porch right before sunrise and it was 30°F out. The reading at the same time out in the yard fluctuated from 25°F to 28°F. I was amazed how much colder this was and did some reading about standard ambient air temperature readings. It seems my thermometer on the porch is in a position very similar to how official measurements are taken. Its about 5 ft. off the ground, under an overhang yet more than 10 ft. from the house and protected from direct sun.

As can be seen my shelter is only 2°F warmer than the ambient are temperature but much warmer than the sky exposed temperature.

The night before, I didn't have the bed spread on and the shelter temperature was equal to the ambient temperature which means it got down to 27°F for about two hours and my tree took some damage. Mangoes start getting damaged at 29°F. Apparently a 75 watt bulb in a shelter of this size without the blanket wasn't enough. Shelters I had that were about half this size with the same protection did much better.

[phoenixtropicals]

Here is the graph of temperatures inside the tent. Low ambient air temperature was 30°F that morning. Temps. start out in the 70's because I brought the thermometers out from inside the house. The spike at the end at 8:40 AM is when the sun came out and the rest is just garbage readings when the thermometer was in my pocket etc.

[phoenixtropicals]

Here are the readings from Monday night (aka The mango growers night from hell). I didn't have a thermometer outside, just in the tent. Low in tent was 27°F. Ambient was the same (no bed spread). Temperature in the open must have been horrible. Probably around 22°F based on my other experience. I had to go to work and left the plastic on. Notice how warm it got in there that day.